Novel Micro-Implant to Measure Intracardiac Pressure in Congenital Heart Patients

描述(申请人提供)：具有功能性单心室(FSV)解剖结构的先天性心脏病患者通常需要在婴儿期和儿童期进行一系列手术，以便为他们提供存活到成年的机会。第二阶段手术被称为半丰坦手术(HFP)，它将全身静脉血从上半身和头部重新输送到肺循环中，而不需要穿过中间的脑室。由于进入肺的血流在很大程度上是一个被动的过程，肺血管内的任何解剖障碍、肺血管阻力增加或显著的心功能不全都可能导致患者的半方坦压力升高。在分期姑息过程的早期，在半-Fontan通路内出现的问题可能会导致Fontan手术期间和Fontan患者一生中并发症的风险增加。因此，保持最佳的半Fontan解剖和生理学对于FSV患者的长期成功和生存是重要的。目前，在大多数机构中，在手术后立即或在等待Fontan期间的门诊环境中常规测量半Fontan通路的压力并不是标准做法。术后监测半Fontan压需要在上半身或颈部静脉留置导管。这有可能导致全身静脉完全血栓形成，这对半方坦患者来说是一个毁灭性的并发症。此外，连续的门诊心导管术测量半方坦压力使婴儿面临手术并发症的风险。因此，为了在ICU和门诊环境中为临床医生提供测量半Fontan压力的手段，研究人员正在开发一种微型压力传感器，可以在第二阶段手术时直接植入半Fontan通路。拟议的植入式压力监测仪将在手术后即刻提供对半Fontan通路的血流动力学评估，而不会有全身静脉血栓形成的风险。在非卧床环境下对半Fontan通路压力进行间歇性测试将使临床医生能够观察压力上升趋势，这可能提供正在发展的问题的早期迹象，并允许在不可逆转的损害发生之前进行更早的干预。这将在没有心导管术相关风险的情况下完成。在这项研究中，研究人员将完成一种微型植入式无线压力传感器的开发。最终将实现设计冻结，并将完成设计控制要求，包括风险分析、生物兼容性测试、无菌和制造工艺，以满足FDA的要求。将进行临床前动物研究，包括慢性GLP动物研究，以确定该设备的体内生物兼容性、功能性和安全性。最后，这项研究将支持研究人员在申请过程中获得FDA的调查设备豁免，用于这些复杂形式的先天性心脏病婴儿的初步可行性研究。

DESCRIPTION (provided by applicant): Congenital heart disease patients with functional single ventricle (FSV) anatomy usually require a series of surgeries during infancy and childhood in order to provide them with a chance to survive into adulthood. The second stage surgery, termed the hemi-Fontan procedure (HFP) re-routes systemic venous blood from the upper body and head into the pulmonary circulation without passing through an intervening ventricular chamber. Because blood flow into the lungs is largely a passive process, any anatomic obstruction within the pulmonary vasculature, elevated pulmonary vascular resistance, or significant ventricular dysfunction can result in patients having elevated hemi-Fontan pressures. Problems that develop within the hemi-Fontan pathway early in the staged palliation process can result in an increased risk for complications during the Fontan operation and throughout a Fontan patient's life. Therefore, maintaining optimal hemi-Fontan anatomy and physiology is important for long term success and survival for FSV patients. Currently, it is not standard practice at most institutions to routinely measure hemi-Fontan pathway pressures in the immediate post- operative period or in the ambulatory setting while awaiting the Fontan. Post-operative monitoring of the hemi- Fontan pressures requires an indwelling catheter in an upper body or neck vein. This has the potential to lead to complete thrombosis of the systemic vein, which is a devastating complication for the hemi-Fontan patient. Furthermore, serial outpatient cardiac catheterizations to measure hemi-Fontan pressures place infants at risk for procedural complications. Therefore, to provide clinicians in the ICU and in the ambulatory setting with the means to measure hemi-Fontan pressures, investigators are developing a miniaturized pressure sensor that can be implanted directly into the hemi-Fontan pathway at the time of the second stage operation. The proposed implantable pressure monitor will provide readily available hemodynamic assessment of the hemi- Fontan pathway during the immediate post-operative period without the risk of systemic venous thrombosis. Interval testing of the hemi-Fontan pathway pressure in the ambulatory setting will allow clinicians to observe for rising pressure trends, which may provide early indication of a problem that is developing and allow for earlier intervention before irreversible damage has occurred. This will be accomplished without the risk associated with cardiac catheterization. During this study investigators will complete the development of a miniature implantable wireless pressure sensor. Final design freeze will be achieved, and design control requirements, including risk analysis, biocompatibility testing, sterility, and manufacturing processes, will be completed to satisfy FDA requirements. Preclinical animal studies will be carried out, including a chronic GLP animal study, to determine the device's in vivo biocompatibility, functionality, and safety profile. Finally, this study will support investigators during the application process to obtain Investigational Device Exemption from the FDA for the initial feasibility studies in infants with these complex forms of congenital heart disease.